Kerry Says U.S. Knew of Iran’s Military Aid to Houthi Rebels

CAIRO — Secretary of State John Kerry has said that the United States knew Iran had been providing military support to the Houthi rebels in Yemen and that Washington “is not going to stand by while the region is destabilized.”

Mr. Kerry’s remarks, in an interview on Wednesday night with “PBS NewsHour,” appeared to be the most direct warning yet from Washington about Iranian support for the Houthi movement, which has allied with security forces loyal to a former leader and has taken control of Yemen’s capital, Sana.

The comments come as the United States has increased its provision of weapons, intelligence and logistical support for a Saudi-led campaign of airstrikes aimed at preventing the Houthis and their allies from dominating Yemen.

Saudi Arabia has contended that the Houthis are essentially an Iranian proxy force, but Western diplomats and analysts have said that, while the Houthis are financially supported by Iran, they are not operating under its control or direction.

Mr. Kerry was also speaking in support of a recent deal with Tehran that would roll back Western economic sanctions in exchange for restrictions on Iran’s nuclear program.

He issued his warnings about Iranian support for the Houthis in the context of seeking to reassure allies, including Saudi Arabia, that the United States could “do two things at the same time.”

He argued that the United States could help push back against Iranian attempts to project its influence around the region, while at the same time rewarding Tehran for providing guarantees that it was not building nuclear weapons.

Mr. Kerry was asked in the interview about Iran’s denials of claims that it was providing military assistance to the Houthis and whether the United States accepted those statements.

“It is just not a fact, they have been,” he said, contradicting the Iranian denials about providing military support. He said that the United States was “very concerned about what is going on there.”

“There are obviously supplies that have been coming from Iran,” he said. “There are a number of flights every single week that have been flying in. We trace those flights, and we know this. We are well aware of the support that Iran has been giving to Yemen, and Iran needs to recognize that the United States is not going to stand by while the region is destabilized, or while people engage in overt warfare across lines — international boundaries of other countries.”

Mr. Kerry appeared to be describing past support and not current activities, because for the last two weeks, Saudi Arabia has imposed an air blockade over Yemen that would have stopped flights from Iran. It was unclear precisely what type of military support Mr. Kerry meant.